JP2002368334A - Surface emitting lasers, photodiodes, their manufacturing methods, and opto-electric hybrid circuits using them - Google Patents

Abstract

(57) Abstract: A surface-emitting laser and a photodiode, which can be firmly mounted even when mounted by flip chip bonding, and enable high-speed modulation, and a method of manufacturing the same and their use. Provided is an opto-electric hybrid circuit. SOLUTION: A light emitting portion 2A and a reinforcing portion 2B are formed in a semiconductor laminated body 2 laminated on a semiconductor substrate 1 via a concave portion 6, and a p-type ohmic electrode 4 and an n-type ohmic electrode are formed on the upper surface of the reinforcing portion 2B. The electrode 5 is formed. The p-type ohmic electrode 4 is buried in the concave portion 6 and is electrically connected to the p-type contact layer 21 through a contact hole 41a formed in the vertical direction in the polyimide. A current can be supplied. In the recess 6, a groove 6a reaching the semiconductor substrate 1 is formed to suppress a parasitic capacitance generated between the p-type ohmic electrode 4 and the n-type ohmic electrode 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface emitting laser used for digital optical communication and a method for manufacturing the same.

[0002]

2. Description of the Related Art Usually, a vertical cavity surface emitting laser (VCS) is used.
EL ｜ Vertical Cavity Surfac
e Emitting Laser) forms a convex light emitting portion by vertically etching a semiconductor laminate in which an active layer and a distributed reflection layer are stacked, and emits a laser beam from a light emitting surface opened on the upper surface of the light emitting portion. It is configured to
Here, in order to generate laser light, upper and lower electrodes sandwiched above and below are formed on the semiconductor laminated body including the light emitting portion via an insulating layer, and a voltage is applied so that a current flows in the thickness direction of the light emitting portion. As a result, a current is supplied to the active layer.

However, according to the surface emitting laser having the above structure, the upper and lower electrodes formed on the upper and lower surfaces and the thin insulating layer formed between the electrodes form a capacitor, and its parasitic capacitance is large. Failure occurs. Therefore, it has been difficult to perform high-speed modulation of the surface emitting laser.

For example, Japanese Patent Application Laid-Open No. Hei 8-116131 discloses
As disclosed in Japanese Unexamined Patent Application Publication, there is proposed means for forming an insulating layer made of a polyimide resin having a thickness between upper and lower electrodes. According to the above proposal, a polyimide resin is buried in a concave portion formed around a convex portion serving as a light emitting portion so that a step with the convex portion is eliminated, and an electrode is laminated on an upper surface of the polyimide resin.

According to the surface emitting laser having the above structure, the distance between the upper and lower electrodes is increased by using a polyimide resin.
Since the parasitic capacitance can be reduced, high-speed modulation of the surface emitting laser has become possible.

[0006]

By the way, in order to increase the density of the surface emitting laser having the above structure, mounting is often performed by flip chip bonding in which electrodes and other semiconductor elements are fixed by soldering with solder bumps or the like. is there.

However, in the surface emitting laser having the above structure, since the electrodes are laminated on the upper surface of the polyimide resin which is softer than the semiconductor material, there is a possibility that the electrode surface may be deformed such as being dented during mounting. In this case, the electrodes may be peeled off, or the surface emitting laser may not be mounted firmly.

Further, since laser light is generated by the upper and lower electrodes sandwiching the semiconductor laminate vertically, it has been necessary to contact the electrodes on the back surface of the semiconductor substrate by wire bonding or the like.

The present invention has been made in view of the above circumstances, and provides a surface emitting laser that can be mounted securely and firmly even when mounting by flip chip bonding, and that enables high-speed modulation. It is an object to provide a manufacturing method thereof.

[0010]

According to the present invention, there is provided a semiconductor laminate which is laminated on a semiconductor substrate and an upper surface thereof, and is divided into a light emitting portion and a reinforcing portion via a concave portion, and is embedded in the concave portion. An insulating material, and a pair of electrodes for applying a voltage so that a current flows in a thickness direction of the light emitting unit, wherein the pair of electrodes has a connection portion with the outside on an upper surface of the reinforcing portion. It is a light emitting laser.

With this configuration, the pair of electrodes are formed so as to have a connection with the outside on the upper surface of the reinforcing portion made of a semiconductor laminate made of a material harder than a conventional polyimide resin. Accordingly, even when mounting is performed by flip chip bonding, deformation such as depression of the electrode surface can be suppressed. Therefore, problems such as peeling of the electrodes can be solved, and the surface emitting laser can be reliably mounted.

In addition, since the pair of electrodes are formed on the upper surface of the reinforcing portion on the same surface, it is not necessary to make contact with the electrode on the back surface by wire bonding or the like, thereby reducing the complexity of mounting the surface emitting laser. It is effective to reduce.

Further, one of the pair of electrodes is a surface emitting laser which is electrically connected to a lower end of the light emitting section through a contact hole extending vertically in the insulating material.

Further, one of the pair of electrodes is electrically connected to the lower end of the light emitting portion through a contact hole extending vertically in the insulating material, so that the pair of electrodes are flush with each other. In this case, it is possible to supply a current in the vertical direction of the light emitting unit, that is, in the thickness direction.

In addition, the bottom surface of the recess reaches the surface of the semiconductor substrate over the entire length thereof in order to disconnect the lower end of the light emitting portion from the lower end of the reinforcing portion.

Further, since the bottom surface of the concave portion is formed so as to reach the surface of the semiconductor substrate over the entire length, the lower end of the light emitting portion and the lower end of the reinforcing portion are electrically disconnected. In addition, the parasitic capacitance generated between the pair of electrodes can be suppressed. That is, further high-speed modulation of the surface emitting laser becomes possible.

Further, a step of vertically etching the semiconductor laminate formed on the semiconductor substrate to form a concave portion for dividing the semiconductor laminate into a light emitting portion and a reinforcing portion, and Forming a groove for disconnecting the lower end of the light emitting portion and the lower end of the reinforcing portion from each other in the vertical direction so as to reach the surface of the semiconductor substrate, and the concave portion including the groove portion. Embedded therein, a step of embedding an insulating substance, a step of forming a contact hole extending vertically in a part of the insulating substance and connecting to a lower end of the light emitting section, and forming a contact hole at an upper end of the light emitting section. Forming a conductive electrode and an electrode conductive to the upper end of the contact hole on the upper surface of the reinforcing portion.

In the step of forming the groove, the groove is formed such that a portion connected to a lower end of the contact hole remains at a lower end of the light emitting section.

Further, the groove is formed so that the portion connected to the lower end of the contact hole remains at the lower end of the light emitting portion, so that one electrode is connected to the lower end of the light emitting portion via the contact hole. It can conduct. Therefore, even if the pair of electrodes is formed on the upper surface of the reinforcing portion, it is possible to supply a current in the thickness direction of the light emitting portion.

Here, the reinforcing portion is a portion which does not function as a light emitting portion of the semiconductor laminated body laminated on the upper surface of the semiconductor substrate, and is a portion which has been removed by etching when a conventional surface emitting laser is manufactured. is there. In the present invention, a pair of electrodes having a connection portion with the outside is formed on the reinforcing portion, which has been removed in the related art.

[0021] Further, a semiconductor laminated body laminated on the upper surface thereof and divided into a light receiving portion and a reinforcing portion via a concave portion, an insulating material embedded in the concave portion, and a light incident portion. And a pair of electrodes for detecting a current flowing in the thickness direction of the light receiving section. The pair of electrodes is a photodiode having a connection portion with the outside on the upper surface of the reinforcing section.

Further, the pair of electrodes are formed so as to have a connection portion with the outside on the upper surface of the reinforcing portion made of a semiconductor laminate made of a material harder than the conventional polyimide resin, so that mounting by flip chip bonding is possible. , It is possible to suppress deformation such as denting of the electrode surface.
Therefore, problems such as peeling of the electrode can be solved, and the photodiode can be reliably mounted.

Further, since the pair of electrodes are formed on the upper surface of the reinforcing portion, which is the same surface, it is not necessary to make contact with the electrode on the back surface by wire bonding or the like, thereby reducing the complexity of mounting the photodiode. It is effective to let.

Further, one of the pair of electrodes is a photodiode which is electrically connected to the lower end of the light receiving section via a contact hole extending vertically in the insulating material.

Also, one of the pair of electrodes is electrically connected to the lower end of the light receiving portion through a contact hole extending vertically in the insulating material, so that the pair of electrodes are in the same plane. Even if it is formed, it is possible to detect the current flowing in the vertical direction of the light receiving section, that is, the thickness direction.

In addition, the bottom surface of the recess reaches the surface of the semiconductor substrate over the entire length thereof in order to disconnect the lower end of the light receiving portion and the lower end of the reinforcing portion.

Further, since the bottom surface of the concave portion is formed so as to reach the surface of the semiconductor substrate over its entire length, the lower end of the light receiving portion and the lower end of the reinforcing portion are electrically disconnected. In addition, the parasitic capacitance generated between the pair of electrodes can be suppressed. That is, it is possible to further increase the bandwidth of the photodiode.

A step of vertically etching the semiconductor laminate formed on the semiconductor substrate to form a concave portion for dividing the semiconductor laminate into a light receiving portion and a reinforcing portion; Further etching in the vertical direction so as to reach the surface of the semiconductor substrate to form a groove for disconnecting the lower end of the light receiving portion and the lower end of the reinforcing portion, and the recess including the groove Inside, a step of embedding an insulating material, a step of forming a contact hole extending vertically in a part of the insulating material and connecting to a lower end of the light receiving section, Forming a conductive electrode and an electrode conductive to the upper end of the contact hole on the upper surface of the reinforcing portion.

In the step of forming the groove, the groove is formed such that a portion connected to the lower end of the contact hole remains at the lower end of the light receiving section.

Further, by forming the groove so that the portion connected to the lower end of the contact hole remains at the lower end of the light receiving portion, one of the electrodes is connected to the lower end of the light receiving portion via the contact hole. It can conduct. Therefore, even if the pair of electrodes is formed on the upper surface of the reinforcing portion, it is possible to detect the current flowing in the thickness direction of the light receiving portion.

An optical waveguide, a mirror for entering the optical waveguide, a mirror for exiting from the optical waveguide,
9. An opto-electric hybrid circuit having at least an electric wiring, wherein the surface emitting laser according to claim 1 to 3, and a laser driving circuit for driving the surface emitting laser with respect to the electric wiring. And an amplifier circuit for detecting a signal from the photodiode are an opto-electric hybrid circuit mounted by flip chip bonding.

Further, the surface emitting laser according to claims 1 to 3, a laser driving circuit for driving the surface emitting laser, the photodiode according to claims 6 to 8, and a signal from the photodiode are provided for the electric wiring. Is mounted by flip-chip bonding, so that a highly reliable opto-electric hybrid circuit can be manufactured.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a surface emitting laser according to the present invention. FIG. 2 is a plan view showing a surface emitting laser according to the present invention.

The surface emitting laser 100 according to the present invention has the structure shown in FIG.
As shown in FIG. 2, a high-resistance semiconductor substrate 1 made of GaAs, and a light emitting unit 2 provided on the upper surface of the semiconductor substrate 1.
A, a semiconductor laminate 2 divided into a reinforcing portion 2B via a concave portion 6, an insulating layer 3 provided on the upper surface thereof, and a p-type ohmic electrode 4 and an n-type ohmic electrode 5 further provided on the upper surface. , Is composed of.

The semiconductor laminate 2 includes a p-type contact layer 21 and a p-type DBR which are sequentially laminated from the upper surface of the semiconductor substrate 1.
It comprises a mirror layer 22, a p-type cladding layer 23, an active layer 24, an n-type cladding layer 25, a current confinement layer 26, an n-type DBR mirror layer 27, and an n-type contact layer 28.

The p-type contact layer 21 is made of p-type GaAs. The p-type DBR mirror layer 22 is a 30-pair multilayer film in which p-type AlAs layers and p-type Al _0.15 Ga _0.85 As layers are alternately stacked. The P-type cladding layer 23 is made of p-type Al
_It consists of _0.5 Ga _0.5 As. The active layer 24 includes a GaAs well layer and an Al _0.3 Ga _0.7 As barrier layer,
The well layer has a multiple quantum well structure composed of three layers. The n-type cladding layer 25 is made of n-type Al _0.5 Ga _0.5 As
Consists of The current confinement layer 26 is made of an n-type AlAs layer. The n-type DBR mirror layer 27 is a 25-pair multilayer film in which n-type AlAs layers and n-type Al _0.15 Ga _0.85 As are alternately stacked. n-type contact layer 28, n-type Al _0.15 G
a _0.85 As.

A semiconductor laminate 2 in which these layers are sequentially formed
Among them, the columnar light emitting portion 2A functioning as a resonator and the surrounding reinforcing portion 2B are divided via a ring-shaped concave portion 6. On the bottom surface of the concave portion 6, a groove portion 6a is formed, which extends from the periphery of the light emitting portion 2A to the semiconductor substrate 1 over the entire periphery except for a part of a substantially rectangular shape in plan view. Here, in the present embodiment, the planar shape of the light emitting section 2A is circular, but the present invention is not limited to this, and may have any shape such as a polygon. Although a part of the planar shape in which the groove 6a is not formed is substantially rectangular, the present invention is not limited to this, and may have any shape such as a circle or a polygon.

A polyimide resin is buried as an insulating material 7 in the recess 6 including the groove 6a. A contact hole 41a is formed in a part of the polyimide resin, and a conductive material is buried in the contact hole 41a.

The current confinement layer 26 of the light emitting section 2A is within a circle having a predetermined diameter at the center of the light emitting section 2A, and an insulating layer 26a made of aluminum oxide is formed outside the circle. In the current constriction layer 26 of the reinforcing portion 2B, a similar insulator layer 26a is formed in a region around several μm around the concave portion. By forming this insulator layer 26a, the current from the p-type ohmic electrode 4 is concentrated at the center of the light emitting section 2A.

The insulating layer 3 is formed of the reinforcing portion 2B except for the portion where the n-type contact layer 28 in the light emitting portion 2A is exposed.
Are formed on the upper surface of the n-type contact layer.

The p-type ohmic electrode 4 is
1 and a circular electrode pad 42 connected thereto. The contact portion 41 comes into contact with the polyimide resin embedded in the concave portion 6 formed on the peripheral edge of the light emitting portion 2A, and also comes into contact with the p-type contact layer 21 through a contact hole 41a extending vertically in the polyimide resin. I have. The electrode pad portion 42 is formed on the upper surface of the n-type contact layer 28 of the reinforcing portion 2B via the insulating layer 3.

That is, the p-type ohmic electrode 4 is in contact with the p-type contact layer 21 through the contact hole 41a extending below the contact portion 41. The material of the p-type ohmic electrode 4 is made of chromium and a gold-zinc alloy.

The n-type ohmic electrode 5 is
1, a circular electrode pad portion 52, and a band-like connecting portion 53 connecting these. The contact section 51 is in contact with the n-type contact layer 28 of the light emitting section 2A, and has a ring shape in plan view. The hole of the ring serves as an emission port of the surface emitting laser 100. Electrode pad part 52
Is the n-type contact layer 2 of the reinforcing portion 2B via the insulating layer 3.
8 is formed on the upper surface. The connecting portion 53 connects the peripheral edge of the contact portion 51 and the peripheral edge of the electrode pad portion 52 with the shortest distance, and is in contact with the polyimide resin.

That is, the n-type ohmic electrode 5 is in contact with the n-type contact layer 28 by the contact part 51. The material of the n-type ohmic electrode 5 is made of a gold-germanium alloy.

In the surface emitting laser 100 having the above configuration, the p-type contact layer 21, the p-type DBR mirror layer 22, the p-type cladding layer 23, the active layer 24, the n-type cladding layer 25, the current confinement layer 26, and the n-type DBR mirror The layer 27, the n-type contact layer 28, the p-type ohmic electrode 4, and the n-type ohmic electrode 5 constitute a vertical cavity surface emitting laser (VCSEL). Here, when a voltage is applied between the respective electrodes, the n-type ohmic electrode 5 formed on the upper surface of the light emitting unit 2A and the light emitting unit 2A via the contact hole 41a.
With the conductive p-type ohmic electrode 4 at the lower end of the light emitting portion, a current flows in the thickness direction of the light emitting portion 2A.
When the current is supplied to the active layer 24, the laser light is emitted vertically upward from the light emitting surface 21A opened on the upper surface of the light emitting unit 2A.

FIG. 9 is a sectional view showing a photodiode according to the present invention. FIG. 10 is a plan view showing a photodiode according to the present invention. The same components as those of the surface emitting laser 100 of the above embodiment are denoted by the same reference numerals,
Detailed description is omitted.

The photodiode 200 according to the present invention comprises:
As shown in FIGS. 9 and 10, a high-resistance semiconductor substrate 1 made of GaAs, and a semiconductor laminate provided on the upper surface of the semiconductor substrate 1 and divided into a light receiving portion 2C and a reinforcing portion 2B via a recess 6 2, an insulating layer 3 provided on the upper surface thereof, and a p-type ohmic electrode 4 and an n-type ohmic electrode 5 further provided on the upper surface.

The difference from the surface emitting laser 100 of the above-described embodiment is that the semiconductor laminate 2 is laminated in order from the upper surface of the semiconductor substrate 1 into the p-type contact layer 21 and the light absorbing layer 2.
9 and an n-type contact layer 28.

The p-type contact layer 21 is made of p-type GaAs. The light absorption layer 29 is made of GaAs. The n-type contact layer 28 is made of n-type Al _0.15 Ga _0.85 As.

In the photodiode 200 having the above structure,
The p-type contact layer 21, the light absorbing layer 29, the n-type contact layer 28, the p-type ohmic electrode 4, and the n-type ohmic electrode 5 constitute a PIN photodiode. Here, the light receiving surface 21 opened on the upper surface of the light receiving unit 2C
Light incident from C is absorbed by the light absorbing layer 29 to generate a current. Then, this current is supplied to the n-type ohmic electrode 5,
The amount of light incident on the light receiving surface 21C is detected by the amplifying circuit 9 described later by the conductive p-type ohmic electrode 4 on the lower end side of the light receiving unit 2C via the contact hole 41a.

FIG. 11 shows a surface emitting laser 10 according to the present invention.
FIG. 2 is a cross-sectional view illustrating a photoelectric circuit 300 using a photodiode 0 and a photodiode 200;

As shown in FIG. 11, the opto-electric hybrid circuit 300 includes a substrate 10 and an optical waveguide 3 provided on the upper surface of the substrate 10.
0, an electric wiring 11, and a surface emitting laser 10 mounted on the electric wiring 11 by flip chip bonding.
0, a laser drive circuit 8, a photodiode 200, and an amplifier circuit 9.

The optical waveguide 30 is a polymer type optical waveguide in which both sides in the thickness direction and both sides in the width direction of the core 32 are covered with the cladding 31. Then, of the two ends of the optical waveguide 30 in the optical waveguide direction, a portion located on the upstream side in the optical waveguide direction has a direction of the laser beam irradiated from the light emitting surface 21A of the surface emitting laser 100 in the thickness direction of the substrate 10. Is changed by 90 degrees to a direction along the surface of the substrate 10, and a mirror 33 that propagates in the core 32 is provided. Also, the optical waveguide 3
The laser light propagating in the core 32 is changed by 90 degrees in the portion on the downstream side in the optical waveguide direction among both ends of the optical waveguide direction 0, and the light receiving surface 2 of the photodiode 200 is changed.
A mirror 34 for making the light enter 1C is provided.

A surface emitting laser 100 is provided on the optical waveguide 30.
Further, an electric wiring 11 for connecting the laser drive circuit 8 or connecting the photodiode 200 and the amplifier circuit 9 is formed. And the surface emitting laser 1
00 and p-type ohmic electrode 4 and n-type ohmic electrode 5 of photodiode 200 and laser drive circuit 8
In addition, stat bumps 12 are formed on electrodes (not shown) of amplifier circuit 9, and these elements are mounted on electric wiring 11 by flip chip bonding.

In the surface emitting laser 100 or the photodiode 200 having the above configuration, the electrode pad portions 42, 5
2 is formed on the upper surface of the reinforcing portion 2B of the semiconductor laminate 2, even if the stat bumps 12 for flip-chip bonding are formed on the upper surfaces of the electrode pads 42, 52, the surfaces of the electrode pads 42, 52 are depressed. Etc. can be suppressed. Therefore, the electrode pad portions 42 and 52
A problem such as peeling of the optical circuit is eliminated.
A highly reliable surface-emitting laser 100 or photodiode 200 that can be reliably mounted on a semiconductor device can be manufactured.
Can be produced.

In addition, since the portion of the semiconductor laminate 2 which has been conventionally removed by etching is left as the reinforcing portion 2B and used, the surface has a high strength for mounting by flip chip bonding without increasing the cost. The light emitting laser 100 or the photodiode 200 can be easily and reliably manufactured.

Furthermore, one p-type ohmic electrode 4 of the pair of electrodes is conductive to the lower end of the light emitting section 2A or the light receiving section 2C through the contact hole 41a, so that both the pair of electrodes are reinforced. Even if it is formed on the upper surface of 2B, it becomes possible to supply a current in the thickness direction of the light emitting section 2A or to take out the current from the light receiving section 2C. By forming a pair of electrodes on the upper surface of the reinforcing portion 2B, it is not necessary to make contact between the electrodes by wire bonding or the like after mounting the flip chip bonding.
This is effective for eliminating the complexity of mounting the 00. In addition, the connection between the laser driving circuit 8 and the electrode of the surface emitting laser 100 or the connection between the photodiode 200 and the electrode of the amplifier circuit 9 on the opto-electric hybrid circuit 300 can be shortened. 100
This is effective for high-speed modulation of the above or for broadening the bandwidth of the photodiode 200.

Further, a groove 6a reaching the semiconductor substrate 1 over the entire periphery is formed on the bottom surface of the concave portion 6 formed on the periphery of the light emitting section 2A or the light receiving section 2C, so that the p-type contact is formed via the contact hole 41a. The p-type ohmic electrode 4 conducting to the layer 21 is conducted only to the lower end of the light emitting section 2A or the light receiving section 2C. Therefore, since the parasitic capacitance between the p-type ohmic electrode 4 and the n-type ohmic electrode 5 is suppressed, the surface emitting laser 10
0 faster modulation or photodiode 200
Has become possible to further broaden the bandwidth.

Next, a method of manufacturing the surface emitting laser 100 according to the embodiment of the present invention will be described with reference to FIGS. 3 to 8 are cross-sectional views illustrating one manufacturing process of the surface emitting laser 100 according to the present invention.

First, as shown in FIG. 3, a p-type contact layer 21 is formed on a high-resistance semiconductor substrate 1 made of GaAs.
p-type DBR mirror layer 22, p-type cladding layer 23, active layer 24, n-type cladding layer 25, current confinement layer 26, n-type DB
An R mirror layer 27 and an n-type contact layer 28 are sequentially stacked.

Each of the semiconductor laminates 2 is formed by metal organic chemical vapor deposition (MOVPE | Metal-Organic Vap).
or Phase Epitaxy). Here, not only the MOVPE method but also the MBE method
(Molecular Beam Epitaxy) method or LPE (Liquid Phase Epitaxy)
axy) method may be used.

Next, a photoresist is applied on the n-type contact layer 28 and then patterned by photolithography to form a resist layer having a predetermined pattern. Next, using this resist layer as a mask, etching is performed by reactive ion etching until the p-type contact layer 21 is exposed, as shown in FIG. Here, the columnar light-emitting portion 2 is provided on the semiconductor laminate 2 through the concave portion 6.
A and its surrounding reinforcement 2B are formed.

Next, in order to leave a portion where the p-type ohmic electrode 4 and the p-type contact layer 21 make contact with each other at the lower end of the light-emitting portion 2A, the light-emitting portion 2A
A substantially rectangular resist layer is formed from the peripheral edge toward the outer circumferential circle of the concave portion 6. Then, using the resist layer as a mask, the semiconductor substrate 1 is further etched halfway by reactive ion etching as shown in FIG.
A groove 6a for element isolation is formed in the recess 6. Here, the p-type contact layer 21 remains in the substantially rectangular portion where the resist layer is formed, and a groove 6a reaching the semiconductor substrate 1 is formed in other exposed portions.

Next, the current constriction layer 26 made of n-type AlAs is exposed to a steam atmosphere at about 400 ° C. for 1 to 30 minutes, whereby the AlAs layer is oxidized from the exposed surface to the inside, and the semiconductor layer made of AlAs Is formed around the insulating layer 26a made of aluminum oxide. Here, the insulator layer 26a is formed in a ring shape around the outer periphery of the light emitting portion 2A except for the central portion and the outer periphery of the concave portion 6, respectively.

Next, as shown in FIG. 6, an insulating material 7 is formed in the recess 6 including the groove 6a formed by etching.
Then, a polyimide precursor is applied, and after curing, a n-type contact layer 28 is exposed, and then a silicon oxide film is formed on the entire surface by a sputtering method or the like. Here, polyimide is buried as an insulating substance 7 in the recess 6 including the groove 6a. As a method of applying the polyimide precursor, any method such as a spin coating method, a dipping method, and a spray coating method may be used.

Next, by photolithography and dry etching, the silicon oxide film on the upper surface of the light emitting portion 2A is removed by etching, and the insulating layer 3 is formed on the upper surface of the reinforcing portion 2B.

Next, as shown in FIG. 7, a recess is formed in the polyimide resin on the side (left side in the drawing) on which the p-type ohmic electrode 4 is to be formed by photolithography and dry etching from the upper surface of the semiconductor laminate 2. A contact hole 41a extending in the vertical direction up to the p-type contact layer 21 left in 6 is formed.

Next, as shown in FIG. 8, a metal layer made of a metal such as chromium and a gold-zinc alloy is formed on the upper surface of the semiconductor laminate 2 by a vacuum evaporation method, and a predetermined pattern is formed by photolithography and dry etching. Is formed.

Next, a photoresist is applied on the upper surface of the semiconductor laminate 2 and then patterned by photolithography to form a resist layer having a predetermined pattern. Then, after forming a metal layer made of a metal such as a gold-germanium alloy on the upper surface of the resist layer by a vacuum deposition method, the metal deposited on the resist layer is removed together with the resist layer by a lift-off method. Here, an n-type ohmic electrode 5 having an opening 21A is formed on the upper surface of the light emitting section 2A. Through the above steps, the surface emitting laser 100 of the present embodiment is completed.

On the other hand, the structure of the photodiode 200 according to the embodiment of the present invention is different from the surface emitting laser 100 according to the embodiment of the present invention only in the structure of the semiconductor laminated body 2. The method is different from the above-described manufacturing method only in the laminated structure of the semiconductor laminated body 2, and therefore, detailed description thereof is omitted.

Here, in the present embodiment, the light emitting section 2
A or only the periphery of the light receiving portion 2C was etched, and the semiconductor laminate 2 was left in other portions to form a reinforcing portion 2B.
As long as the semiconductor laminate 2 is left at least on the lower surface of the portion where the mounting is performed by flip chip bonding, the formation site, the formation area, and the formation shape of the reinforcing portion 2B are not limited thereto.

Further, in the present embodiment, the planar shape of the p-type ohmic electrode 4 and the n-type ohmic electrode 5 is circular, but is not limited to this, and may be any shape such as a triangle and a quadrangle.

In the present embodiment, the contact hole 41a is formed in the p-type ohmic electrode 4 to enable conduction with the lower end of the light emitting section 2A or the light receiving section 2C. Alternatively, as long as it can conduct with the lower end of the light receiving section 2C, the present invention is not limited to this, and the p-type and the n-type in the present embodiment can all be reversed.

Further, in the present embodiment, a polyimide resin is used as the insulating substance 7, but the present invention is not limited to this, and any substance such as an acrylic resin or an epoxy resin may be used.

Further, in this embodiment, the surface emitting laser 100 for emitting laser light upward is described. However, the present invention is not limited to this, and a surface emitting laser for emitting laser light downward may be used. Similarly, in the present embodiment, the photodiode 200 receives the laser light from above, but is not limited to this, and may be a photodiode that receives the laser light from below.

Further, a plurality of surface emitting lasers 100 or photodiodes 200 according to the present embodiment can be two-dimensionally arranged in parallel to form an array. In this case, the p-type contact layer 21 of each light emitting unit 2A or each light receiving unit 2C does not need to be separated for each element, and may be a common electrode. Thereby, the number of electrodes can be reduced.

[0078]

As described above, according to the surface emitting laser according to the first aspect or the photodiode according to the fourth aspect, the pair of electrodes has the connection portion with the outside on the upper surface of the reinforcing portion. With such a configuration, even if mounting by flip-chip bonding is performed, it is possible to reliably fix the semiconductor device, so that a highly reliable surface-emitting laser or photodiode can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a surface emitting laser according to the present invention.

FIG. 2 is a plan view showing a surface emitting laser according to the present invention.

FIG. 3 is a cross-sectional view illustrating one manufacturing process of the surface emitting laser according to the present invention.

FIG. 4 is a sectional view illustrating one manufacturing process of the surface emitting laser according to the present invention.

FIG. 5 is a sectional view illustrating one manufacturing process of the surface emitting laser according to the present invention.

FIG. 6 is a cross-sectional view illustrating one manufacturing process of the surface emitting laser according to the present invention.

FIG. 7 is a sectional view illustrating one manufacturing process of the surface emitting laser according to the present invention.

FIG. 8 is a cross-sectional view illustrating one manufacturing process of the surface emitting laser according to the present invention.

FIG. 9 is a cross-sectional view showing a photodiode according to the present invention.

FIG. 10 is a plan view showing a photodiode according to the present invention.

FIG. 11 is a sectional view showing an opto-electric hybrid circuit according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 Semiconductor laminated body 2A Light emitting part 2B Reinforcement part 2C Light receiving part 3 Insulating layer 4 P-type ohmic electrode 5 N-type ohmic electrode 6 Concave part 6a Groove part 7 Insulating substance (polyimide resin) 8 Laser drive circuit 9 Amplifier circuit 10 Substrate 11 Electrical wiring 12 Stud bump 21 P-type contact layer 22 p-type DBR mirror layer 23 p-type cladding layer 24 active layer 25 n-type cladding layer 26 current confinement layer 26 a insulator layer 27 n-type DBR mirror layer 28 n-type contact layer REFERENCE SIGNS LIST 29 light absorbing layer 30 optical waveguide 41 contact part 41 a contact hole 42 electrode pad part 51 contact part 52 electrode pad part 53 connecting part 100 surface emitting laser 200 photodiode 300 opto-electric hybrid circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Harada 3-35-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Takeo Kaneko 3-5-35, Yamato, Suwa-shi, Nagano Seiko-Epson In-house F-term (Reference) 2H047 KA04 KB09 LA09 MA07 QA05 5F049 MA04 NA09 NA15 NA20 NB01 PA14 QA20 RA07 RA10 SE09 SE11 SE15 SE20 SS04 SS10 TA11 UA05 5F073 AA74 AA89 AB15 AB17 AB25 BA02 CA04 CA05 CB30 DA30 DA27 DA27 DA27

Claims (11)

[Claims] A semiconductor laminated body laminated on an upper surface thereof and divided into a light emitting portion and a reinforcing portion via a concave portion, an insulating material embedded in the concave portion, and the light emitting portion. And a pair of electrodes for applying a voltage so that a current flows in a thickness direction of the reinforcing member, wherein the pair of electrodes has a connection portion with the outside on an upper surface of the reinforcing portion. 2. The device according to claim 1, wherein one of the pair of electrodes is electrically connected to a lower end of the light emitting unit via a contact hole extending vertically in the insulating material. Surface emitting laser. 3. The semiconductor device according to claim 1, wherein the bottom surface of the concave portion reaches the surface of the semiconductor substrate over the entire length thereof so as to disconnect the lower end portion of the light emitting portion and the lower end portion of the reinforcing portion. The surface emitting laser according to claim 1 or 2, wherein: 4. A step of vertically etching a semiconductor laminate formed on a semiconductor substrate to form a concave portion for dividing the semiconductor laminate into a light-emitting portion and a reinforcing portion; Forming a groove for disconnecting the lower end of the light emitting portion and the lower end of the reinforcing portion from each other in the vertical direction so as to reach the surface of the semiconductor substrate, and the recess including the groove A step of embedding an insulating material therein; a step of forming a contact hole extending vertically in a part of the insulating material and connecting to a lower end of the light emitting unit; Forming a conductive electrode and an electrode conductive to an upper end of the contact hole on an upper surface of the reinforcing portion. 5. The method according to claim 4, wherein, in the step of forming the groove, the groove is formed such that a portion connected to a lower end of the contact hole remains at a lower end of the light emitting unit. Manufacturing method of surface emitting laser. 6. A semiconductor laminated body laminated on a semiconductor substrate, an upper surface thereof, and divided into a light receiving portion and a reinforcing portion via a concave portion, an insulating material embedded in the concave portion, and light incidence And a pair of electrodes for detecting a current flowing in the thickness direction of the light receiving unit. The pair of electrodes has a connection portion with the outside on an upper surface of the reinforcing unit. 7. The light-receiving section according to claim 6, wherein one of said pair of electrodes is electrically connected to a lower end of said light-receiving section via a contact hole extending vertically in said insulating material. Photodiode. 8. The semiconductor device according to claim 8, wherein the bottom surface of the concave portion reaches the surface of the semiconductor substrate over the entire length thereof so as to disconnect the lower end portion of the light receiving portion and the lower end portion of the reinforcing portion. The photodiode according to claim 6 or 7, wherein 9. A step of vertically etching a semiconductor laminated body formed on a semiconductor substrate to form a concave portion which divides the semiconductor laminated body into a light receiving portion and a reinforcing portion; Forming a groove for disconnecting the lower end of the light receiving portion and the lower end of the reinforcing portion from each other in the vertical direction so as to reach the surface of the semiconductor substrate, and the recess including the groove A step of embedding an insulating material therein, a step of forming a contact hole extending vertically in a part of the insulating material and connecting to a lower end of the light receiving section, and an upper end of the light receiving section. Forming a conductive electrode and an electrode conductive to an upper end of the contact hole on an upper surface of the reinforcing portion. 10. The method according to claim 9, wherein in the step of forming the groove, the groove is formed such that a portion connected to a lower end of the contact hole remains at a lower end of the light receiving unit. Photodiode manufacturing method. 11. An opto-electric hybrid circuit having at least an optical waveguide, a mirror for entering the optical waveguide, a mirror for exiting from the optical waveguide, and an electric wiring, wherein: A surface emitting laser according to any one of claims 1 to 3, a laser driving circuit for driving the surface emitting laser, a photodiode according to claims 6 to 8, and an amplifier circuit for detecting a signal from the photodiode. ,
Is mounted by flip chip bonding.